drivers/md/raid10.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _RAID10_H
   3 #define _RAID10_H
   4
   5 struct raid10_info {
   6         struct md_rdev  *rdev, *replacement;
   7         sector_t        head_position;
   8         int             recovery_disabled;      /* matches
   9                                                  * mddev->recovery_disabled
  10                                                  * when we shouldn't try
  11                                                  * recovering this device.
  12                                                  */
  13 };
  14
  15 struct r10conf {
  16         struct mddev            *mddev;
  17         struct raid10_info      *mirrors;
  18         struct raid10_info      *mirrors_new, *mirrors_old;
  19         spinlock_t              device_lock;
  20
  21         /* geometry */
  22         struct geom {
  23                 int             raid_disks;
  24                 int             near_copies;  /* number of copies laid out
  25                                                * raid0 style */
  26                 int             far_copies;   /* number of copies laid out
  27                                                * at large strides across drives
  28                                                */
  29                 int             far_offset;   /* far_copies are offset by 1
  30                                                * stripe instead of many
  31                                                */
  32                 sector_t        stride;       /* distance between far copies.
  33                                                * This is size / far_copies unless
  34                                                * far_offset, in which case it is
  35                                                * 1 stripe.
  36                                                */
  37                 int             far_set_size; /* The number of devices in a set,
  38                                                * where a 'set' are devices that
  39                                                * contain far/offset copies of
  40                                                * each other.
  41                                                */
  42                 int             chunk_shift; /* shift from chunks to sectors */
  43                 sector_t        chunk_mask;
  44         } prev, geo;
  45         int                     copies;       /* near_copies * far_copies.
  46                                                * must be <= raid_disks
  47                                                */
  48
  49         sector_t                dev_sectors;  /* temp copy of
  50                                                * mddev->dev_sectors */
  51         sector_t                reshape_progress;
  52         sector_t                reshape_safe;
  53         unsigned long           reshape_checkpoint;
  54         sector_t                offset_diff;
  55
  56         struct list_head        retry_list;
  57         /* A separate list of r1bio which just need raid_end_bio_io called.
  58          * This mustn't happen for writes which had any errors if the superblock
  59          * needs to be written.
  60          */
  61         struct list_head        bio_end_io_list;
  62
  63         /* queue pending writes and submit them on unplug */
  64         struct bio_list         pending_bio_list;
  65         int                     pending_count;
  66
  67         spinlock_t              resync_lock;
  68         atomic_t                nr_pending;
  69         int                     nr_waiting;
  70         int                     nr_queued;
  71         int                     barrier;
  72         int                     array_freeze_pending;
  73         sector_t                next_resync;
  74         int                     fullsync;  /* set to 1 if a full sync is needed,
  75                                             * (fresh device added).
  76                                             * Cleared when a sync completes.
  77                                             */
  78         int                     have_replacement; /* There is at least one
  79                                                    * replacement device.
  80                                                    */
  81         wait_queue_head_t       wait_barrier;
  82
  83         mempool_t               *r10bio_pool;
  84         mempool_t               *r10buf_pool;
  85         struct page             *tmppage;
  86         struct bio_set          *bio_split;
  87
  88         /* When taking over an array from a different personality, we store
  89          * the new thread here until we fully activate the array.
  90          */
  91         struct md_thread        *thread;
  92
  93         /*
  94          * Keep track of cluster resync window to send to other nodes.
  95          */
  96         sector_t                cluster_sync_low;
  97         sector_t                cluster_sync_high;
  98 };
  99
 100 /*
 101  * this is our 'private' RAID10 bio.
 102  *
 103  * it contains information about what kind of IO operations were started
 104  * for this RAID10 operation, and about their status:
 105  */
 106
 107 struct r10bio {
 108         atomic_t                remaining; /* 'have we finished' count,
 109                                             * used from IRQ handlers
 110                                             */
 111         sector_t                sector; /* virtual sector number */
 112         int                     sectors;
 113         unsigned long           state;
 114         struct mddev            *mddev;
 115         /*
 116          * original bio going to /dev/mdx
 117          */
 118         struct bio              *master_bio;
 119         /*
 120          * if the IO is in READ direction, then this is where we read
 121          */
 122         int                     read_slot;
 123
 124         struct list_head        retry_list;
 125         /*
 126          * if the IO is in WRITE direction, then multiple bios are used,
 127          * one for each copy.
 128          * When resyncing we also use one for each copy.
 129          * When reconstructing, we use 2 bios, one for read, one for write.
 130          * We choose the number when they are allocated.
 131          * We sometimes need an extra bio to write to the replacement.
 132          */
 133         struct r10dev {
 134                 struct bio      *bio;
 135                 union {
 136                         struct bio      *repl_bio; /* used for resync and
 137                                                     * writes */
 138                         struct md_rdev  *rdev;     /* used for reads
 139                                                     * (read_slot >= 0) */
 140                 };
 141                 sector_t        addr;
 142                 int             devnum;
 143         } devs[0];
 144 };
 145
 146 /* bits for r10bio.state */
 147 enum r10bio_state {
 148         R10BIO_Uptodate,
 149         R10BIO_IsSync,
 150         R10BIO_IsRecover,
 151         R10BIO_IsReshape,
 152         R10BIO_Degraded,
 153 /* Set ReadError on bios that experience a read error
 154  * so that raid10d knows what to do with them.
 155  */
 156         R10BIO_ReadError,
 157 /* If a write for this request means we can clear some
 158  * known-bad-block records, we set this flag.
 159  */
 160         R10BIO_MadeGood,
 161         R10BIO_WriteError,
 162 /* During a reshape we might be performing IO on the
 163  * 'previous' part of the array, in which case this
 164  * flag is set
 165  */
 166         R10BIO_Previous,
 167 /* failfast devices did receive failfast requests. */
 168         R10BIO_FailFast,
 169 };
 170 #endif